Spas, also commonly known as hot tubs, are generally deep vacuum formed tubs having a smooth acrylic interior surface or liner. The tubs are provided with a number of fixtures including water jet assemblies that provide hydrotherapy to users of the spa when the spa is filled with water.
Spas are typically manufactured by heating an acrylic sheet to a forming temperature, stretching the sheet onto a mold, and holding the sheet against the mold by applying a vacuum between the mold surface and the sheet. After forming the acrylic liner, holes are then manually cut through the liner for various components including the water jets. A typical spa may include anywhere from 30-120 or more water jets, and construction of the spa requires cutting 30-120 holes in the acrylic liner to accommodate the jets. Once the cutouts for the jets have been made, jet assemblies must be placed in each cutout, which includes placing a gasket between a wall fitting of the jet assembly and the interior surface of the tub, providing the wall fitting through the cutout, and threading a jet valve body onto the wall fitting from the back of the tub such that the wall fitting and the jet valve body sandwich the tub wall. A bead of caulk is utilized to seal the jet valve body to the back of the tub wall.
FIGS. 1 and 2 illustrate the back of a prior art spa and, in particular, illustrate a plurality of jet assemblies 12 that are mounted in cutouts in the spa liner 14. As shown therein, each jet assembly 12 includes fittings for connecting a water supply line 16 and an air supply line 18 thereto. Each air supply line 18 is connected to a pressurized air source (not shown), and each water supply 16 line is connected to a water manifold 20. In operation, water is drawn from the tub by a pump, passed through a heating element to heat the water to a desired temperature, and delivered to the manifold 20 and supply lines 16 to the jet assemblies 12. Water supplied to the jets 12 is mixed with air from the air supply lines 18 to make the stream from the jets 12 more robust.
Notably, however, spas with this type of circulation system are extremely costly and time consuming to manufacture, and are prone to leaking. In particular, making each cutout and assembling and mounting upwards of 120 jet assemblies by hand is extremely time consuming and tedious and often requires two people. Moreover, each jet assembly, each fitting on each jet assembly for the water and air lines, and each connection to the water manifold is a potential leak point. As will be readily appreciated, this presents upwards of 360 or more possible places in the spa that leaks may occur. Moreover, existing spas are especially leak-prone where metal components are used (due to corrosion).
From a business standpoint, therefore, spas are extremely time consuming and costly to manufacture due to the manual labor necessary to install each individual jet assembly and the dedicated water and air supply lines for each jet. Moreover, repair and warranty costs are often a concern, mostly due to the high number of potential leakage points, as discussed above.
In addition, spas of this type typically require the use of two 5 hp motors to run the pumps that push the water through the circulation system. This requirement stems mainly from the high degree of hydraulic impedance resulting from the many twists and turns of the numerous water supply lines. As will be readily appreciated, therefore, the use of two motors, or a single motor having a higher output, adds additional costs to the spa as a whole.
In view of the above, there remains a need for a jet system for a spa that is less prone to leakage, lowers impedance and decreases overall repair and warranty costs. In addition, there is a need for a jet system for a spa that can be easily customized to provide a desired degree and type of hydrotherapy.